why do i gain so much weight but manage to lose it within that same day?

You’re not gaining weight, your body weight just fluctuates throughout the day depending on how much food and liquids you are consuming - they have their own weight. The same with your height - your height changes throughout the day due to gravity, but it doesnt mean you are actually getting taller or shorter.

thats why its best to weigh yourself at the same time everyday

it could be that you have a fast metabolism like me, which would then mean that you can just eat for a long time and not get fat… just don’t do what i do, which is to abuse this fast metabolism by trying to create food no one has dared to try to eat before (a double stacked triple cheeseburger)

Undigested food weights. After it has been digested you loose the weight. Most of your digestion comes at night while sleeping. One should get at least 5 1/2 hours of uninterrupted sleep everynight. When one does this one can maintain his or her weight. Also, the longer one sleeps the more weight comes off. It’s not always exercise that does it. Excursize keeps the mussels firm.

It all depends on your metabolism. Some people just burn calories quicker than others. However, if you’re maintaining the same weight and not losing nor gaining too much - then that’s fine and your healthy, in that aspect. It’s most likely a genetic thing. Mind you, weight is just a small fraction of your overall health - so don’t worry too much about your weight, look more at your daily nutrition intake and juxtapose with your daily routines and such.